Species ca. 25 (10 in the flora): North America, Mexico, West Indies, Central America, South America.

As pointed out by R. M. Tryon (1956), J. T. Mickel (1979), and many others, Notholaena in the broad sense is poorly defined and difficult to distinguish from either Cheilanthes or Pellaea . North American taxa traditionally assigned to Notholaena represent at least four distinct evolutionary lineages (M. D. Windham 1986). In order to clarify species relationships and generic boundaries among cheilanthoid ferns, Notholaena is defined here in a very restricted sense. The pubescent, nonfarinose species (such as N . newberryi ) have been placed in Cheilanthes following R. M. Tryon and A. F. Tryon (1982). The scaly, nonfarinose taxa of the N . sinuata complex have been transferred to Astrolepis for reasons discussed by D. M. Benham and M. D. Windham (1992). The glabrous and farinose species related to Pellaea (e.g., N . jonesii and N . dealbata ) have been placed in Argyrochosma (M. D. Windham 1987). The species retained in Notholaena following this reorganization (i.e., members of the farinose N . grayi -- N . standleyi alliance) form a coherent, monophyletic group found only in the Western Hemisphere. The correct generic name for this group is in dispute because Notholaena has been lectotypified by several authors citing three different type species. The rules of priority favor the first typification (by J. Smith in 1875) based on N . trichomanoides (Linnaeus) Desvaux, which is definitely a member of the group here called Notholaena . R. E. G. Pichi-Sermolli (1989), however, urged acceptance of the typification by C. Christensen ([1905--]1906). Both the second and third lectotypifications of Notholaena were based on species unrelated to the North American taxa discussed here. If Smith's typification is overturned, the correct generic name for our species will be Chrysochosma (J. Smith) Kümmerle.